There are increasing numbers of patients who are being fed completely via parenteral fluids for short and long periods of time. The most obvious examples are patients undergoing post-operative care. But there are also many patients who for various reasons cannot take a diet of normal food and are fed enterally with defined enteral preparations, often containing relatively low levels of fat in general or essential fatty acids (EFAs) in particular (e.g. M. Pettei et al, "Essential fatty acid deficiency with the use of chemically-defined diets", Gastroenterology 1989; 96:A391).
A number of complications can develop in these patients. The include intestinal atrophy, biliary abnormalities, insulin resistance, accumulation of fat in the liver, abnormal activation of the reticulo-endothelial system (particularly with parenteral lipids), abnormal lipoprotein levels and increased protein catabolism. This invention addresses these issues and three of them in particular all of which can occur with both enteral and parenteral artificial nutrition regimes.
(1) There is relatively rapid atrophy of the small intestine and of the villi protruding into the lumen. The villi are the small finger like processes of the intestinal mucosa which project into the intestinal lumen and which are important in increasing the surface area available for the absorption of intestinal contents. As a result, absorption of foods becomes inefficient and when patients start taking normal oral food they cannot utilise it properly. They develop many adverse symptoms such as gastrointestinal motility disburbances, including diarrhoea, pain and malabsorption.
(2) There is rapid accumulation of fine precipitated material (sludge) in bile. This makes the bile thick and viscous and leads to a high risk of developing gall stones.
(3) There can be severe accumulation of fat in the liver, causing fatty liver which may disrupt both the structure and function of the liver.